1) Field of the Invention
The present invention relates to an operation support unit, an operation support system, and an operation support method that automatically optimize a control quantity for each control object of a printer.
2) Description of the Related Art
In printers, the degree of ink key opening, the quantity of dampening water, and the adjustment quantities to paper supplying and discharging sections, are important control quantities that have an influence upon the quality of a print. It is necessary that these control quantities be suitably adjusted for each job according to printing conditions (e.g., ink kind, paper kind, an image area rate, etc.). Adjustments to the control quantities depend on the skill of a person who operates a printer.
However, in the case where adjustments to the control quantities depend on the skill of an operator, there is a fear that a difference in quality between prints will occur according to the degree of operator""s skill. In general, trial printing is repeatedly performed until a print of satisfactory quality (hereinafter referred to as an OK sheet) is obtained. In the case of an unskilled operator, there is a fear that a great deal of trial printing will be required until the OK sheet is obtained and therefore a large quantity of paper will be wasted. Because of this, there has been a strong demand for the development of a system capable of accurately and easily making adjustments to a control quantity according to printing conditions without depending on the skill of an operator so that a printer can be easily operated.
As such a system, an operation support system is disclosed, for example, in Japanese Laid-Open Patent Publication No. HEI 11-342597. In the support system, various kinds of control quantities for a printer are automatically controlled based on information about the interaction between control media, stored in an expert system.
In operation of a printer, to early achieve control objectives (e.g., stabilization of operation in a steady state, early starting of a printer, etc.), it is extremely important to select and control suitable control objects (which are to be controlled) from a great number of control objects for a printer according to the control objectives. In the case where a plurality of control objects must be controlled to achieve a single control objective, the quantities that the control objects are controlled (hereinafter referred to as control quantities) influence each other and therefore it is important to set optimal control quantities as a whole.
However, in the aforementioned publication, there is almost no concrete information on the above-mentioned relationship between control quantities and on a method of controlling a printer. Based on this publication, it is fairly difficult to support operation of a print with stability.
The above-mentioned publication also discloses that a great number of dispersed reference points on an n-dimension space actually detected are interpolated and, based on this, color control and density control are performed. This implies that various kinds of operation information on the interaction between control media are stored in an expert system and, based on the operation information, various control characteristics are estimated, and that based on the various control characteristics, various control quantities for a printer are set.
The aforementioned operation information, however, has errors in measurement, and errors due to the influence of various conditions that cannot be realistically taken into consideration. It is extremely important in executing the operation support of a printer with stability to estimate control characteristics with high reliability, based on a great number of data groups having such errors. In the above-mentioned publication there is no information on these points.
The present invention has been made in view of the problems described above. Accordingly, it is the primary objective of the present invention to provide an operation support unit, an operation support system, and an operation support method for a printer which are capable of supporting operation of the printer with reliability and stability.
To achieve the aforementioned objective of the present invention, there is provided an operation support unit for automatically setting control quantities of control objects for a printer, based on printing conditions for the printer, printing-quality information on a print, and mechanical information on the printer, and then outputting the set control quantities to a printer control unit which controls operation of the control objects of the printer, the operation support unit comprising:
information storage means in which the printing conditions, the printing-quality information, and the mechanical information are correlated and stored as a sequence of data sets;
allocation means for setting a suppression factor according to a control mode, and then allocating a plurality of control objects for the printer effective in suppressing the suppression factor, as a control group;
information collection means for collecting a set of data that is under printing conditions nearly coinciding with the present predetermined printing conditions, from the sequence of data sets stored in the information storage means; and
control-quantity set means for setting, for each the suppression factor, a principal axis component which represents a distributed characteristic of the data set collected by the information collection means, as a characteristic line for the control objects selected as the control group, and then setting control quantities of the control objects, based on the characteristic line in order to suppress the suppression factor.
With this construction, a characteristic line with extremely high reliability is obtained based on a set of data, and a control quantity for a control object is set based on the characteristic line. As a result, there is an advantage that for the predetermined control objects of the printer, optimum control quantities can be reliably set under the present operating condition and that operation of the printer can be supported with reliability and stability.
In the operation support unit of the present invention, the allocation means gives the orders of priority to the plurality of control objects of the control group in the order that the effect of suppressing the suppression factor is higher. The quantity set means sets within the standard operating range a control quantity for a control object whose priority order is higher, based on the characteristic line and, when the control quantity alone cannot suppress the suppression factor, sets a control quantity for the control object having the next highest priority order, based on the characteristic line.
With this construction, there is an advantage that operation support can be efficiently performed and that operation is safely performed within the standard operating range.
In the operation support unit of the present invention, when control quantities for the plurality of control objects in the control group are simultaneously preset because the suppression factor cannot be suppressed by controlling the control quantity of a single control object of the control group within the standard operating range, the control quantities are set so that the sum total of varied quantities of the control objects that are simultaneously preset becomes the minimum.
With this construction, there is an advantage that operation support can be efficiently performed.
In the operation support unit of the present invention, the information collection means collects a set of data from among the plurality of data sets stored in the information storage means, when one condition is that an overall streak rate for an image is nearly the same as the present overall streak rate.
In this case, control is performed according to the overall streak rate having a great influence on the control quantity of the control object, so that there is an advantage that operation support can be efficiently performed.
In accordance with the present invention, there is provided an operation support system comprising:
a printing condition output unit for outputting printing conditions to a printer;
a printing quality detection unit for detecting printing-quality information on a print;
a mechanical information detection unit for detecting mechanical information on the printer;
a printer control unit for controlling operation of various kinds of control objects of the printer; and
the aforementioned operation support unit;
wherein the information storage means correlates the printing conditions from the printing condition output unit, the printing-quality information from the printing quality detection unit, and the mechanical information from the mechanical information detection unit and stores them as a sequence of data sets.
Furthermore, in accordance with the present invention, there is provided an operation support method of automatically optimizing control quantities of control objects for a printer, comprising the steps of:
setting an suppression factor which is suppressed according to a control mode, and then allocating a plurality of control objects for the printer effective in suppressing the suppression factor, as a control group;
collecting a set of data that is under printing conditions nearly coinciding with the present predetermined printing conditions, from a great number of data sets in which printing conditions, printing-quality information, and mechanical information are correlated; and
setting, for each the suppression factor, a principal axis component which represents a distributed characteristic of the collected data set, as a characteristic line for the control objects selected as the control group, and then setting control quantities of the selected control objects, based on the characteristic line in order to suppress the suppression factor.
According to the operation support system and the operation support method of the present invention, a control group is allocated to each of the suppression factors, and a set of data that is under printing conditions nearly coinciding with the present predetermined printing conditions is collected from a great number of data sets in which printing conditions, printing-quality information, and mechanical information are correlated. And a principal axis component which represents a distributed characteristic of the collected set of data is set as a characteristic line for the control objects selected as the control group. Therefore, a characteristic line with extremely high reliability is obtained based on a set of data, and a control quantity for a control object is set based on the characteristic line. As a result, there is an advantage that for the predetermined control objects of the printer, optimum control quantities can be reliably set under the present operating condition and that operation of the printer can be supported with reliability and stability.